Flavonoid glycosides from Olax mannii: Structure elucidation and effect on the nuclear factor kappa B pathway

Revision of NMR assignment for Morin-3-O-glucoside and microbial production of Morin-2'-O-glucoside

Morin is a flavonol having 2',4'-dihydroxy group on B-ring identified especially in Moraceae plants. While morin is widely known, its glycosides are relatively rare. To the best of our knowledge, morin-3-O-glucoside (1) was first reported in 2008. However, the reported chemical shift values of 1 were unsatisfactory with those of the aglycone, morin, which is rather similar to quercetin-3-O-glucoside (2). Therefore, we prepared morin-3-O-glucoside (1) by microbial transformation of morin with Cunninghamella sp., and the NMR assignment was reinvestigated. The microbial culture also produced another compound (3). The NMR and MS analyses of 3 revealed it as a novel compound, morin-2'-O-glucoside (3).In this study, the revision of the NMR assignment of morin-3-O-glucoside (1), and the preparation and structural elucidation of a novel compound, morin-2'-O-glucoside (3), were described.

Structure-based molecular networking, molecular docking, dynamics simulation and pharmacokinetic studies of Olax subscorpioidea for identification of potential inhibitors against selected cancer targets

The rationale at the basis of targeted approach in oncology is radically shifting-from development of highly specific agents aiming at a single target towards molecules interfering with multiple targets. This study was performed to isolate and characterize bioactive molecules from Olax subscorpioidea stem and investigate their potentials as multi-targeted inhibitors against selected non-small cell lung cancer, breast cancer and chronic myelogenous leukemia oncogenic targets. Three compounds: β-sitosterol (1), α-amyrin (2) and stigmasterol (3) were isolated. The structures of 1 - 3 were elucidated by analysis of their spectroscopic data (NMR, MS and IR). To the best of our knowledge, this is the first time these compounds were isolated from O. subscorpioidea stems. Furthermore, integrated analysis of MS/MS data using the Global Natural Products Social Molecular Networking (GNPS) workflow enabled dereplication and identification of 26 compounds, including alkaloids (remerine, boldine), terpenoids (3-hydroxy-11-ursen-28,13-olide, oleanolic acid), flavonoids (kaempferitrin, olax chalcone A) and saponins in O. subscorpioidea stem. Molecular docking studies revealed that some of the compounds, including olax chalcone A (-9.2 to -10.9 kcal/mol), 3-Hydroxy-11-ursen-28,13-olide (-6.6 to -10.2 kcal/mol), α-amyrin (-6.6 to -10.2 kcal/mol), stigmasterol (-7.7 to -10.1 kcal/mol), β-Sitosterol (-7 to -9.9 kcal/mol) and kaempferitrin (-7.7 to -9 kcal/mol) possessed good inhibitory potentials against selected cancer targets, when compared with reference inhibitors (-8.4 to -13.7 kcal/mol). A few of these compounds were shown to have considerable to favorable pharmacokinetic and drug-likeness properties. This study provides some rationale for the use of O. subscorpioidea in ethnomedicinal management of cancer and identifies some potential anticancer agents.Communicated by Ramaswamy H. Sarma.

A new flavonoid glycoside from the aerial parts of Diplotaxis erucoides (L.) DC. growing in Algeria

The phytochemical study of the 70% ethanol extract of the aerial parts of Diplotaxis erucoides afforded one new flavonoid glycoside, namely kaempferol-3-O-[α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside]-7-O-α-L-rhamnopyranoside (1), named diploerucoside A and seven known compounds including one flavonoid (2), one phenolic glycoside (3), one monoterpene (4), one triterpene (5), one sitosterol (6) and two monoglycerolipids (7, 8). Their structures were established by extensive spectroscopic analysis including 1 D- and 2 D-NMR (1H, 13C, 1H-1H COSY, HSQC and HMBC), mass spectrometry (HR-ESI-MS) and by comparison with the data reported in the literature.

Investigation of Chemical Constituents and Antioxidant Activity of Biologically Active Plant-Derived Natural Products

The aim of this publication is to present rapid screening methods (visual/colorimetric) that will enable quick identification of the presence of biologically active compounds in aqueous solutions. For this reason, 26 plant extracts obtained by ultrasound-assisted extraction were analysed for the content of these compounds. Higher plants, used as a raw material for extraction, are common in Europe and are easily available. The article proposes a comparison of various protocols for the identification of various compounds, e.g., phenolic compounds (phenols, tannins, anthocyanins, coumarins, flavones, flavonoids), vitamin C, quinones, quinines, resins, glycosides, sugars. Initial characterisation of the composition of plant extracts using fast and inexpensive methods allows you to avoid the use of time-consuming analyses with the use of advanced research equipment. In addition, the antioxidant activity of plant extracts using spectrophotometric methods (DPPH, ABTS, FRAP assay) and quantitative analysis of plant hormones such as abscisic acid, benzoic acid, gibberellic acid, indole acetic acid, jasmonic acid, salicylic acid, zeatin, zeatin riboside, and isipentenyl adenine was performed. The obtained results prove that the applied visual methods show different sensitivity in detecting the sought chemical compounds. Therefore, it is necessary to confirm the presence or absence of bioactive substances and their concentration using modern analytical methods.

Newboulasides A and B, two new caffeic acid glycosides from Newbouldia laevis with α-amylase inhibitory activity

Chemical investigation of the ethanol extract of the leaves of Newbouldia laevis (P. Beauv) led to the isolation of two new caffeic acid glycosides, Newboulasides A (1) and B (2). The structures of these compounds were determined on the basis of extensive spectroscopic methods, including 1D-, 2D-NMR and MS data. The extracts and fractions and the isolated compounds were evaluated for their inhibition of α-amylase enzyme activity. The extract showed inhibition of α-amylase activity with IC₅₀ value of 102.91 µg/mL, while the isolated compounds (1 and 2) exhibited pronounced inhibition with IC₅₀ values of 4.95 and 4.44 µg/mL respectively, comparable to the standard - Acarbose with IC₅₀ value of 4.05 µg/mL. Our findings demonstrated that the inhibition of α-amylase activity may be part of the mechanisms through which N. leavis exhibits antidiabetic effect.

Glycosides from Medicinal Plants as Potential Anticancer Agents: Emerging Trends Towards Future Drugs

Background:

Cancer continues to be a global burden, despite the advancement of various technological and pharmaceutical improvements over the past two decades. Methods for treating cancer include surgery, radiotherapy and chemotherapy in addition to other specialized techniques. On the other hand, medicinal plants have been traditionally employed either as the complementary medicine or dietary agents in the treatment and management of cancer. Medicinal plants are a rich source of secondary metabolites with interesting biological and pharmacological activities. Among these metabolites, glycosides are naturally occurring substances and have outstanding therapeutic potential and clinical utility.

Methods:

Different medical research engines such as, GoogleScholar, PubMed, SpringerLink, ScienceDirect were used to collect related literature on the subject matter. In this regard, only peer-reviewed journals were considered.

Results:

Emerging results showed that numerous glycosides isolated from various plants possessed marked anticancer activity against a variety of cancer cell lines. Accordingly, the aim of the present review is to shed light on the anticancer effects of glycosides, analyze possible mechanisms of action, and highlight the role of these natural agents as complementary and alternative medicine in combating and managing cancer.

Conclusion:

The glycosides isolated from different plants demonstrated potent cytotoxic effects against various cancer cell lines in initial preclinical studies. The anticancer effect was mediated through multiple mechanisms; however further detailed studies are needed to understand the full potential of glycosides for clinical utility.

Dietary Indigenous Cinnamon (Cinnamomum osmophloeum) Leaf Powder Reduces Plasma Lipid in Hypercholesterolemia Hamsters

Indigenous cinnamon ( Cinnamomum osmophloeum Kaneh) is a native tree species in Taiwan and has been reported to have various bioactivities including insecticidal, larvicidal, and antimicrobial effects. The chemical finger print of C. osmophloeum is similar to that of commercial cinnamon species with lower coumarin content. The present study was aimed to investigate the antidyslipidemia effects of indigenous cinnamon ( Cinnamomum osmophloeum Kaneh) leaf powder (CoLP) on hypercholesterolemia hamsters. Hyperlipidemia was induced by high-cholesterol (HChol) diet for 4 weeks. Two percent and 5% CoLP, and gemfibrozil (positive control; 0.25%) were administered for 10 weeks following HChol diet. Control groups were fed with normal diet (ND) or ND+5% CoLP. Behavioral, physiological, and serum biochemical parameters were determined. We found that oral administration of CoLP for 10 weeks significantly reduced the HChol-induced increase of total cholesterol (TC), triglyceride, and low-density lipoprotein levels in plasma of hamsters. In addition, HChol-induced elevation of serum glutamic oxaloacetic transaminase and glutamic pyruvic transaminase levels was significantly reversed by CoLP in a dose-dependent manner, whereas blood urea nitrogen and creatinine levels were unaffected. Further standard diagnostic tests support that consumption of CoLP did not show any behavioral and morphological changes in hamsters. Furthermore, chemical composition analysis revealed that two new flavanol glycosides, kaempferol-3- O-α-l-rhamnopyranosyl-(1→2)-α-l-arabinofuranosyl-7- O-α-l-rhamnopyranoside (4) and kaempferol-3- O-β -d-apiofuranosyl-(1→2)-α-l-arabinofuranoside (5) along with 4 known flavonoid glycosides were identified in leaves of C. osmophloeum. Taken together, these results concluded that CoLP possessed strong antidyslipidemic effects. Therefore, C. osmophloeum leaves could be a safe food supplement for treating hypercholesterolemia.

Plant-derived Glycosides with α-Glucosidase Inhibitory Activity: Current Standing and Future Prospects

Background:

The α-glucosidase (EC 3.2.1.20), a calcium-containing intestinal enzyme which is positioned in the cells which cover the intestinal microvilli brush border. The carbohydrates require metabolism by α-glucosidase before being absorbed into the small intestine, and as a result, this enzyme represents a significant drug target for the effective management of diabetes. There are few α- glucosidase inhibitors in the clinical practice that is challenged by several limitations. Thus, new effective and safe therapeutic agents in this class are required. In this regard, plant secondary metabolites are a very promising source to be investigated. Herein in this review, we have focused on the preclinical studies on various glycosides with in vitro α-glucosidase inhibitory activity.

Methods:

The literature available on various websites such as GoogleScholar, PubMed, Scopus. All the peer-reviewed articles were included without considering the impact factor.

Results:

The surveyed literature revealed marked inhibitory profile of various glycosides derived from plants, and some of them were extremely potent relatively to the standard, acarbose in preclinical trials and exhibited multiple targeted effects.

Conclusion:

Keeping in view the results, these glycosides are strong candidates for further, more detailed studies to ascertain their clinical potential and for effective contribution in effective management of diabetes, where multiple targets are required to address

HPLC-DAD finger printing, antioxidant, cholinesterase, and α-glucosidase inhibitory potentials of a novel plant Olax nana

BACKGROUND

The medicinal importance of a novel plant Olax nana Wall. ex Benth. (family: Olacaceae) was revealed for the first time via HPLC-DAD finger printing, qualitative phytochemical analysis, antioxidant, cholinesterase, and α-glucosidase inhibitory assays.

METHODS

The crude methanolic extract of O. nana (ON-Cr) was subjected to qualitative phytochemical analysis and HPLC-DAD finger printing. The antioxidant potential of ON-Cr was assessed via 1,1-diphenyl,2-picrylhydrazyl (DPPH), 2,2-azinobis[3-ethylbenzthiazoline]-6-sulfonic acid (ABTS) and hydrogen peroxide (H2O2) free radical scavenging assays. Furthermore, acetylcholinesterase (AChE) & butyrylcholinesterase (BChE) inhibitory activities were performed using Ellman's assay, while α- glucosidase inhibitory assay was carried out using a standard protocol.

RESULTS

The qualitative phytochemical analysis of ON-Cr revealed the presence of secondary metabolites like alkaloids, flavonoids, tannins, sterols, saponins and terpenoids. The HPLC-DAD finger printing revealed the presence of 40 potential compounds in ON-Cr. Considerable anti-radical activities was revealed by ON-Cr in the DPPH, ABTS and H2O2 free radical scavenging assays with IC50 values of 71.46, 72.55 and 92.33 μg/mL, respectively. Furthermore, ON-Cr showed potent AChE and BChE inhibitory potentials as indicated by their IC50 values of 33.2 and 55.36 μg/mL, respectively. In the α-glucosidase inhibition assay, ON-Cr exhibited moderate inhibitory propensity with an IC50 value of 639.89 μg/mL.

CONCLUSIONS

This study investigated Olax nana for the first time for detailed qualitative phytochemical tests, HPLC-DAD finger printing analysis, antioxidant, anticholinesterase and α-glucosidase inhibition assays. The antioxidant and cholinesterase inhibitory results were considerable and can provide scientific basis for further studies on the neuroprotective and anti-Alzheimer's potentials of this plant. ON-Cr may further be subjected to fractionation and polarity guided fractionation to narrow down the search for isolation of bioactive compounds.